1. Technical Field
The invention relates to a guide rail and link chain for a chain saw used for finishing work on concrete, stone and masonry and in particular to a guide rail having coolant channels.
2. Description of the Prior Art
One such link chain for a chain saw is known from the German Publication DE No. 3,332,051 A1. Here, the guide rail, also called the "sword", is provided on the lengthwise side with additional rails of metal. The guide rail is designed hollow. The hollow space serves as a channel for coolant, and on the side surfaces of the additional rails, coolant channels are arranged. The respective link chain consists of rollers, supported on pegs which are joined with each other by guide and connecting members. The rollers run on the outer surfaces of the additional rails, and the chain is turned, at the front end of the guide rail, over a chain wheel. The guide members of the chain are fastened to the cutting plates set with diamonds, which serve as cutting tools.
Although the chain can be constantly fed through the guide rail with coolant and lubricant, such guide rail and link chain systems have high wear and a short life. The dust from the cutting plates and that from the cut, settle on the additional rails, the guide members and the rollers which wears these metal parts away to the point of destruction. The cutting dust also penetrates between all the sliding surfaces, and the allowable clearance between the parts is very quickly exceeded through wear. Since such chains are very expensive, they cannot be economically used because of the rapid wear. The frequent replacement of chains necessary, and the interruption of operation cause high operation costs also.